Impact Certificate Minter (ICM) is an open-source protocol extension that embeds UN SDG sub-targets and measurable impact intensity indicators into a machine-readable metadata schema, enabling standardized and comparable SDG-aligned impact claims. It combines a mint-first, post-validation architecture with an EAS-compatible attestation layer, AI-assisted anomaly detection, and developer SDKs to deliver verifiable, tamper-resistant proof for biodiversity, waste management, and municipal climate reporting applications.